Re: [PATCH v6 md-6.18 11/11] md/md-llbitmap: introduce new lockless bitmap

[Yu Kuai]

Hi,

在 2025/08/26 17:52, Paul Menzel 写道:
> It’d be great if you could motivate, why a lockless bitmap is needed  > compared to the current implemention.

Se the performance test, old bitmap have global spinlock and is bad with
fast disk.

[snip the typo part]

> How can/should this patch be tested/benchmarked?

There is pending mdadm patch, rfc verion can be used. Will work on
formal version after this set is applied.

> --- a/drivers/md/md-bitmap.h
> +++ b/drivers/md/md-bitmap.h
> @@ -9,10 +9,26 @@
>    #define BITMAP_MAGIC 0x6d746962
> +/*
> + * version 3 is host-endian order, this is deprecated and not used for new
> + * array
> + */
> +#define BITMAP_MAJOR_LO        3
> +#define BITMAP_MAJOR_HOSTENDIAN    3
> +/* version 4 is little-endian order, the default value */
> +#define BITMAP_MAJOR_HI        4
> +/* version 5 is only used for cluster */
> +#define BITMAP_MAJOR_CLUSTERED    5  > Move this to the header in a separate patch?

I prefer not, old bitmap use this as well.

Thanks,
Kuai